<?php

/**
 * Complex filter to handle filtering for many to one relationships,
 * such as terms (many terms per node) or roles (many roles per user).
 *
 * The construct method needs to be overridden to provide a list of options;
 * alternately, the value_form and admin_summary methods need to be overriden
 * to provide something that isn't just a select list.
 */
class views_handler_filter_many_to_one extends views_handler_filter_in_operator {

    function init(&$view, $options) {
        parent::init($view, $options);
        $this->helper = new views_many_to_one_helper($this);
    }

    function option_definition() {
        $options = parent::option_definition();

        $options['operator']['default'] = 'or';
        $options['value']['default'] = array();

        return $options;
    }

    function operators() {
        $operators = array(
            'or' => array(
                'title' => t('Is one of'),
                'short' => t('or'),
                'short_single' => t('='),
                'method' => 'op_helper',
                'values' => 1,
                'ensure_my_table' => 'helper',
            ),
            'and' => array(
                'title' => t('Is all of'),
                'short' => t('and'),
                'short_single' => t('='),
                'method' => 'op_helper',
                'values' => 1,
                'ensure_my_table' => 'helper',
            ),
            'not' => array(
                'title' => t('Is none of'),
                'short' => t('not'),
                'short_single' => t('<>'),
                'method' => 'op_helper',
                'values' => 1,
                'ensure_my_table' => 'helper',
            ),
        );
        // if the definition allows for the empty operator, add it.
        if (!empty($this->definition['allow empty'])) {
            $operators += array(
                'empty' => array(
                    'title' => t('Is empty (NULL)'),
                    'method' => 'op_empty',
                    'short' => t('empty'),
                    'values' => 0,
                ),
                'not empty' => array(
                    'title' => t('Is not empty (NOT NULL)'),
                    'method' => 'op_empty',
                    'short' => t('not empty'),
                    'values' => 0,
                ),
            );
        }

        return $operators;
    }

    var $value_form_type = 'select';

    function value_form(&$form, &$form_state) {
        parent::value_form($form, $form_state);

        if (empty($form_state['exposed'])) {
            $this->helper->options_form($form, $form_state);
        }
    }

    /**
     * Override ensure_my_table so we can control how this joins in.
     * The operator actually has influence over joining.
     */
    function ensure_my_table() {
        // Defer to helper if the operator specifies it.
        $info = $this->operators();
        if (isset($info[$this->operator]['ensure_my_table']) && $info[$this->operator]['ensure_my_table'] == 'helper') {
            return $this->helper->ensure_my_table();
        }

        return parent::ensure_my_table();
    }

    function op_helper() {
        if (empty($this->value)) {
            return;
        }
        $this->helper->add_filter();
    }

}
